Archives Of Health News Blog From Medicineworld.Org

February 6, 2009, 6:26 AM CT

Energy drinks: The coffee of a new generation?

It's not uncommon for students to consume energy drinks to increase their concentration as they study throughout the night. "Energy drinks are the coffee of a new generation," says Stphanie Ct, nutritionist with Extenso, a Universit de Montral health and nutrition think-tank. "These drinks are made up of sugar and caffeine and can have a negative impact on health".

As per a 2008 report by Agriculture and Agri-Food Canada, 1.5 billion cans of Red Bull were sold in the United States in 2004. Consumption in Canada is said to be comparable and it is a growing trend for 18-to 24-year-olds. This market segment is broadening as younger children are beginning to consume these drinks before doing physical activity.

But these drinks aren't recommended to either athletes or children under the age of 12. "Energy drinks don't hydrate the body efficiently," says Ct. "Because they have too much sugar. And caffeine doesn't necessarily improve physical performance. In high quantities it can increase the risks of fatigue and dehydration".

Several studies have demonstrated that strong doses of caffeine can increase hypertension, cause heart palpitations, provoke irritability and anxiety as well as cause headaches and insomnia. Health Canada does not recommend consuming more than two cans per day.........

Young teens really are shortsighted

As per popular stereotype, young teenagers are shortsighted, leaving them prone to poor judgment and risky decision-making when it comes to issues like taking drugs and having sex. Now a newly released study confirms that teens 16 and younger do think about the future less than adults, but explains that the reasons may have less to do with impulsivity and more to do with a desire to do something exciting.

The study, by researchers at Temple University, the University of California, Los Angeles, Georgetown University, the University of California, Irvine, and the University of Colorado, is reported in the January/February 2009 issue of the journal Child Development

The scientists looked at more than 900 individuals ranging in age from 10 to 30 and from an ethnically and socio-economically diverse group to determine how people of different ages think about the future consequences of their decisions. They used a new questionnaire and an experimental task called delay discounting, which measures the extent to which people prefer immediate but smaller rewards over delayed but larger ones.

Compared with adults, the scientists found, teenagers consider the future less and prefer immediate rewards over delayed ones (for example, $700 today versus $1,000 a year from now). But it may not be impulsivity that guides their lack of forethought. Instead, the study observed that teens are shortsighted more due to immaturity in the brain systems that govern sensation seeking than to immaturity in the brain systems responsible for self-control.........

Exploring genetic causes of schizophrenia

A newly released study shows that schizophrenia is caused, at least in part, by large, rare structural changes in DNA referred to as copy number variants (CNVs) not the tiny, single letter alterations (single nucleotide polymorphisms (SNPs) that researchers have pursued for years. The findings are published February 6 in the open-access journal PLoS Genetics

Schizophrenia is one of the most common psychiatric disorders, but researchers have yet to determine significant genetic links. Over the past two decades, dozens of genes and SNPs have been identified as possible candidates, but the current study dismisses them.

"The literature is replete with dozens of genes and SNPs identified as linked to schizophrenia," says first author Anna Need, PhD, a postdoctoral associate in the Center for Human Genome Variation at the Duke Institute for Genome and Sciences Policy. "But we systematically retested all the leading candidates and concluded that most, if not all of them, are false positives." Need says she believes the prior studies were too small to properly assess the role of SNPs.

Need worked with senior author David Goldstein, of the Center for Human Genome variation, and a team of geneticists to scan the genome of schizophrenia patients and healthy controls for SNPs and copy number variants (CNVs). While none of the previously heralded SNPs appeared significant in schizophrenia, several CNVs emerged as potentially causative.........

Vitamin D and MS related gene

Vitamin D containing food itmes

Scientists have found evidence that a direct interaction between vitamin D and a common genetic variant alters the risk of developing multiple sclerosis (MS). The research, published on 6 February in the open-access journal PLoS Genetics, suggests that vitamin D deficiency during pregnancy and the early years may increase the risk of the offspring developing MS during the later part of life.

MS is the most common disabling neurological condition affecting young adults. More than 85,000 people in the UK and 2.5 million worldwide are thought to suffer from the condition, which results from the loss of nerve fibres and their protective myelin sheath in the brain and spinal cord, causing neurological damage.

The causes of MS are unclear, but it has become evident that both environmental and genetic factors play a role. Prior studies have shown that populations from Northern Europe have increased MS risk if they live in areas receiving less sunshine. This supports a direct link between deficiency in vitamin D, which is produced in the body through the action of sunlight, and increased risk of developing the disease.

The largest genetic effect by far comes from the region on chromosome six containing the gene variant known as DRB1*1501 and from adjacent DNA sequences. Whilst one in 1,000 people in the UK are likely to develop MS, this number rises to around one in 300 amongst those carrying a single copy of the variant and one in 100 of those carrying two copies.........

Selling of personalized medicine prematurely?

We appears to be a long way off from using genetics to reliably gauge our risks for specific diseases, say scientists at the University of Pittsburgh Graduate School of Public Health as per a research findings published on Feb. 5 in the online journal PLoS Genetics. Yet, a number of companies currently offer personalized genetic testing for diseases like cancer, heart disease and diabetes, and tout the ability of DNA testing to predict future health risks.

"The rapid discovery of new genetic risk factors is giving us vitally important insights into human health, but a strong association between these factors and disease risk may not reliably predict which health issues a specific individual will face in the future," said Daniel E. Weeks, Ph.D., senior author and professor of human genetics and biostatistics at the University of Pittsburgh Graduate School of Public Health. "Our study indicates that even though we can paint a picture of our genetic makeup with current tests, this may not be enough to help us understand our individual risk for disease".

The study focused on single nucleotide polymorphisms, or SNPs variations in short DNA sequences that have been associated with the presence of particular diseases, and that exist in the millions in the human genome. Many companies currently offer individualized estimates for disease risks based on genome-wide SNP genotyping. These tests typically scan 500,000 to 1 million SNPs, searching for only a handful linked to a specific disease.........

Converting adult stem cells to embryonic-like stem cells

Stem cells

The simple recipe researchers earlier discovered for making adult stem cells behave like embryonic-like stem cells just got even simpler. A new report in the February 6th issue of the journal Cell, a Cell Press publication, shows for the first time that neural stem cells taken from adult mice can take on the characteristics of embryonic stem cells with the addition of a single transcription factor. Transcription factors are genes that control the activity of other genes.

The discovery follows a 2006 report also in the journal Cell that showed that the introduction of four ingredients could transform differentiated cells taken from adult mice into "induced pluripotent stem cells" (iPS) with the physical, growth, and genetic characteristics typical of embryonic stem cells (http://www.eurekalert.org/pub_releases/2006-08/cp-wff080906.php). Pluripotent refers to the ability to differentiate into most other cell types. The same recipe was later shown to work with human skin cells as well (http://www.eurekalert.org/pub_releases/2007-11/cp-srt111307.php).

Subsequent studies observed that the four-ingredient recipe could in some cases be pared down to just two or three essential ingredients, said Hans Schler of the Max Planck Institute for Molecular Biomedicine in Gera number of. "Now we've come down to just one that is sufficient. In terms of the biology, it's really quite amazing".........

Vaccination programs showing its effectiveness

"Conventional wisdom and conventional theory tells us that when infection can potentially be spread to almost everyone in a community, such as for measles, a disease outbreak can never be contained using voluntary vaccination," says Chris Bauch and Ana Persic, scientists from the University of Guelph. "However, our work shows conventional wisdom appears to be wrong for diseases that are spread primarily through close contact, such as smallpox." Their findings are reported in the open-access journal PLoS Computational Biology on February 6th.

Prior studies have suggested that voluntary programs cannot be 100% effective due to the self-interested behavior of individuals. However, most mathematical models used in these studies assume that populations mix homogenously in effect, that an individual is just as likely to be infected by a complete stranger as by a close friend or family member. But that is not how infections spread with diseases like smallpox or SARS, which are predominantly to close social contacts.

In this newly released study, Bauch and Perisic analyze "free-rider" effects under voluntary vaccination for vaccine-preventable diseases where disease transmission occurs in a social network. Individuals choose whether to vaccinate based on the risk of infection from their neighbors and any risks linked to the vaccine itself. Neighbors of an infected person will vaccinate as soon as their neighbor's symptoms appear, so when neighborhood size is small, voluntary vaccination results in rapid containment of an outbreak. As neighborhood size increases, a threshold is reached beyond which the infection can break through due to the decisions of neighbours who choose not to vaccinate.........

Alcohol advertising may lead to underage drinking

Alcohol advertising and marketing may lead to underage drinking. A large systematic review of more than 13,000 people, reported in the open access journal BMC Public Health, suggests that exposure to ads and product placements, even those supposedly not directed at young people, leads to increased alcohol consumption.

Lesley Smith and David Foxcroft from Oxford Brookes University collated information from seven rigorously selected studies, featuring information on 13,255 participants. This systematic review, funded by the Alcohol and Education Research Council (AERC), is the first to study the effects of advertising, product placement in films, games, sporting events and music videos, depictions of drinking in various media, and exposure to product stands in shops. As per Smith, "Our work provides strong empirical evidence to inform the policy debate on the impact of alcohol advertising on young people, and policy groups may wish to revise or strengthen their policy recommendations in the light of this stronger evidence".

The authors observed that exposure to TV alcohol advertisements was linked to an increased tendency to drink, as were magazine advertisements and concession stands at sporting events or concerts. Hours spent watching films, playing games and watching music videos also correlated with young peoples' tendency to consume alcoholic beverages. Smith said, "All seven studies demonstrated significant effects across a range of different exposure variables and outcome measures. One showed that for each additional hour of TV viewing per day the average risk of starting to drink increased by 9% during the following 18 months. Another observed that for each additional hour of exposure to alcohol use depicted in popular movies there was a 15% increase in likelihood of having tried alcohol 13 to 26 months later".........

No increased risk of ovarian cancer from fertility drugs

The use of fertility drugs does not increase a woman's risk of developing ovary cancer, finds a large study from Danish scientists published on bmj.com today.

During the past three decades there has been considerable debate as to whether use of fertility drugs increases a woman's risk of developing ovary cancer. Prior studies have given conflicting results and concerns remain, especially for women who undergo several cycles of therapy or who never succeed in becoming pregnant.

So Allan Jensen and his colleagues at the Danish Cancer Society examined the effects of fertility drugs on ovary cancer risk by using data from the largest cohort of infertile women to date.

The study involved 54,362 women with infertility problems referred to all Danish fertility clinics between 1963 and 1998. 156 of these women had ovary cancer. After adjusting for several risk factors, the scientists assessed the effects of four groups of fertility drugs over an average period of 16 years.

They found no overall increased risk for ovary cancer after use of any fertility drug. They also found no increased risk among women who had undergone 10 or more cycles of therapy or among those who did not become pregnant.

Eventhough the authors did observe a statistically significant increase in risk of the most common serious type of ovary cancer among women who had used the drug clomiphene, they stress that this was probably a chance association.........

Those inactive and overweight preschool children

The rate of childhood obesity has risen significantly in the United States, with a number of children becoming overweight at younger ages. At the same time, the number of preschoolers in center-based programs is also on the rise. Now a newly released study finds that, contrary to conventional wisdom, preschoolers don't move around a lot, even when they're playing outside.

The study, by an interdisciplinary team of scientists at the University of South Carolina (USC), Michigan State University, and East Carolina University and led by Professor Russell R. Pate (at USC), is reported in the January/February 2009 issue of the journal Child Development

Using information from the Children's Activity and Movement in Preschools Study (CHAMPS), a project funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the scientists looked at 3-, 4-, and 5-year olds enrolled in 24 community-based preschool programs.

They observed that the preschoolers were inactive for much of their preschool day, with 89 percent of physical activity characterized as sedentary. Even when they played outside, a time when children are expected to move around, 56 percent of their activities were sedentary.

Furthermore, teachers very rarely encouraged the children to be physically active. But when balls and other items were made available, particularly outside, and when they had open spaces in which to play, the children were more likely to be active.........

Did you know?Studies in monkeys and women suggest that unlike traditional estrogen therapy, a diet high in the natural plant estrogens found in soy does not increase the risk of uterine cancer in postmenopausal women, according to Mark Cline, D.V.M., Ph.D., an associate professor of comparative medicine at Wake Forest University Baptist Medical Center.